You can use Fraps. It's probably the most commonly used application. There are other ways as well.
Tech Support Rule #1 - They will lie to you. Usually intentionally.
I don't know how much time you're willing (or have) for this project but you may also want to look into Demo Recording. I can't speak from experience but it may be something to look at. There are a few guides and such at Paragon Wiki.
And while Fraps is probably the best thing to use, I know it can do things like leave watermarks if you don't pay for it. I've used the WeGame client to record videos that I thought looked good.
type /demorecord "title" (without the "") when you're done recording /demostop. There will be a new folder in your CoH folder under the title "Demos". To what the video drag the file over the CoH desktop icon and it should open auto may take a few mins launch. You can edit the .demo file in Notepad, and there is also a demo editor that someone made, same for a demo launcher. The benefit to the demo is that is removes the UI, if you were to record it with fraps it would record everything. Most people record the demo and then fraps the demo for a clean look.
"while some people would say fish, cow, ambush!"-Ice9
Hello, this thread had been cross-posted, and both threads received some good answers to the OP's question. I'm going to close this thread down, and if anyone would like to chime in with other suggestions for recording video in CoH, please use the other thread in Player Questions:
http://boards.cityofheroes.com/showthread.php?t=253028
Thanks!
I know that this has been asked before, but I do not recall where to find it, Anyone out there know how to record an in game video? I am wanting to put together a tribute video to a local TV personality in my home area and I was wondering where to start.